130 likes | 281 Views
Segments and Congruence. Section 1.2. Vocabulary. The real number that corresponds to a point is the coordinate of the point. Vocabulary. The distance between points A and B, written as AB, is the absolute value of the difference of the coordinates of A and B. Vocabulary.
E N D
Segments and Congruence Section 1.2
Vocabulary The real number that corresponds to a point is the coordinate of the point.
Vocabulary The distance between points A and B, written as AB, is the absolute value of the difference of the coordinates of A and B.
Vocabulary A rule that is accepted without proof is called a postulate. A rule that can be proved is called a theorem.
Ruler Postulate The points on a line can be matched one to one with the real numbers.
Segment Addition Postulate If B is between A and C, then AB + BC = AC. If AB + BC = AC, then B is between A and C.
Maps The cities shown on the map lie approximately in a straight line. Use the given distances to find the distance from Lubbock, Texas, to St. Louis, Missouri. The distance from Lubbock to St. Louis is about 740 miles. ANSWER EXAMPLE 2 Apply the the Segment Addition Postulate SOLUTION Because Tulsa, Oklahoma, lies between Lubbock and St. Louis, you can apply the Segment Addition Postulate. LS = LT + TS = 380 + 360 = 740
In Exercises 3 and 4, use the diagram shown. 3. Use the Segment Addition Postulate to find XZ. ANSWER xz = 73 for Examples 1 and 2 GUIDED PRACTICE SOLUTION xz = xy + yz Segment addition postulate = 23 + 50 Substitute 23 for xy and 50 for yz = 73 Add
Vocabulary Line segments that have the same length are called congruent segments. Lengths are equal (=). Figures are congruent ().
Vocabulary To show that two segments are congruent in a drawing we use tick marks. A B C D
Assignment • P. 12; 1-19